This proposal seeks support to create a new type of ventilator which operates by electrical stimulation of the motor nerves and muscles of respiration, using skin-surface electrodes placed on the chest. Trains of very short-duration electrical stimuli are used so that unwanted cardiac stimulation will not occur. We have termed this technique electroventilation (EV). The secret of selective stimulation of respiratory, but not heart muscle and autonomic nerves, lies in the use of very short-duration pulses, which exploit differences in membrane time constants between cardiac muscle and respiratory nerves. Preliminary studies show that electroventilation produces substantial tidal volumes in the anesthetized dog, exceeding normal resting tidal volume several fold. The research involves studies on dog, pigs, and baboons to work out details of the optimum stimulus patterns and electrode locations. We also propose to create and evaluate an experimental demand electroventilator, which will monitor inspiration by the impedance method and, if it is not present, begin electroventilation automatically. A special electronic design will preserve the ability to monitor the electrocardiogram during electroventilation. The electroventilator will also include alarms for electrode disconnection. In the final stage of research (to be addressed in a future proposal), the device will be tested in patients under anesthesia.